To increase the return on investment of new VA investments in prevention programs, it will be necessary to identify which patient characteristics identify Veterans who have better outcomes in each program and which characteristics identify Veterans who might require alternative prevention programs. The purpose of this CREATE proposal is to systematically evaluate the heterogeneity of treatment effects (HTE) across the three prevention trials to be conducted as part of the Prevention CREATE Lab. We propose to conduct this study in close collaboration with the National Center for Health Promotion and Disease Prevention (NCP), which is the VACO Program Office charged with implementing several major programs as part of VHA's Preventive Care Program transformational sub-initiative, including an enterprise-wide Health Risk Assessment (HRA), a four-site demonstration of the Diabetes Prevention Program (DPP), and a five-site Telephone Lifestyle Coaching program. These prevention interventions are unlikely to be equally effective for all Veterans, so HTE assessment is critical to help target appropriate programs to the appropriate patients, leading to more efficient allocation of resources. To date, a number of statistical methods have been used to evaluate HTE but appropriate multivariate methods are rarely used. Attention to HTE during clinical trial design, conduct, and analysis is necessary for proper inference about treatment effects and for minimizing risk in clinical care. The purpose of this project is to leverage a comprehensive set of patient characteristics to be captured in the three other CREATE trials to determine which Veterans realize the greatest benefit from PACT HRA shared decision-making, prevention group visits, and web-based physical activity interventions (CREATE Projects 1-3). This study addresses the CREATE application's overall goal by assessing heterogeneity in treatment effects, which will inform VHA how to target programs to Veteran needs resulting in the largest impact at the lowest possible cost. The proposed study has two primary aims: Aim #1: Determine the participant characteristics associated with response to treatment in the 3 interventions in this CREATE proposal. Aim #2: Determine the relationship between VA expenditures and participant characteristics associated with response to treatment. That is, do patterns of heterogeneity in treatment effects translate to similar patterns of heterogeneity in VA expenditures? Secondary Aim: Determine the participant characteristics associated with increased per-protocol adherence in the 3 interventions in this CREATE proposal. Results from the proposed study will complement the main analyses of the 3 CREATE trials that will assess overall effectiveness of the HRA shared decision-making program, group prevention coaching, and web-based physical activity interventions. In addition, the results will enable VHA to determine which multidimensional subgroups of Veterans would be best served by each of the interventions when scaled at a national level. This proposal addresses a long term goal of developing decision support that VHA can use in prevention programming to effectively improve the health of Veterans. This CREATE proposal is responsive to HSR&D Priority Area C (Healthcare Informatics) because it will develop a systematic approach to assessing HTE leading eventually to decision support systems that can incorporate multiple Veteran characteristics to prevent chronic health conditions.